// 实现这个项目的构建任务

const { src, dest, parallel, series, watch} = require('gulp');

const del = require('del');
const browser = require('browser-sync');
const bs = browser.create();

const loadPlugins = require('gulp-load-plugins');
const plugins = loadPlugins();

let data = {};
try {
  data = require('./pages.config.js');
} catch {
  
}

const clean = () => {
  return del(['dist','temp']);
}

const style = () => {
  return src('src/assets/styles/*.scss', { base: 'src' })
    .pipe(plugins.sass({outputStyle:"expanded"}))
    .pipe(dest('temp'))
}
const script = () => {
  return src('src/assets/scripts/*.js', { base: 'src' })
    .pipe(plugins.babel({presets:['@babel/preset-env']}))
    .pipe(dest('temp'))
}
const page = () => {
  return src('src/*.html', { base: 'src' })
    .pipe(plugins.swig({ data }))
    .pipe(dest('temp'))
}

const image = () => {
  return src('src/assets/images/**', { base: 'src' })
    .pipe(plugins.imagemin())
    .pipe(dest('dist'))
}

const font = () => {
  return src('src/assets/fonts/**', { base: 'src' })
    .pipe(plugins.imagemin())
    .pipe(dest('dist'))
}

const extra = () => {
  return src('public/**', { base: 'public' })
    .pipe(dest('dist'))
}

const serve = () => {
  watch('src/assets/styles/*.scss', style)
  watch('src/assets/scripts/*.js', script)
  watch('src/*.html', page)
  watch([
    'src/assets/images/**',
    'src/assets/fonts/**',
    'public/**'
  ], bs.reload)
  bs.init({
    notify: false,
    open: false,
    port: 2080,
    files: 'files/**',
    server: {
      baseDir: ['temp','src','public'],
      routes: {
        '/node_modules': 'node_modules'
      }
    }
  })
}

const useref = () => {
  return src('temp/*.html', { base: 'temp' })
    .pipe(plugins.useref({ searchPath: ['temp', '.'] }))
    //html、js、css
    .pipe(plugins.if(/\.js$/, plugins.uglify()))
    .pipe(plugins.if(/\.css$/, plugins.cleanCss()))
    .pipe(plugins.if(/\.html$/, plugins.htmlmin({
      collapseWhitespace: true,//去掉html文件中的空行
      minifyCSS: true,//压缩html中的css代码
      minifyJS: true//压缩html中的js代码
    })))
    .pipe(dest('dist'))
}

const compile = parallel(style, script, page);
const build = series(
  clean,
  parallel(
    series(compile, useref),
    image,
    font,
    extra)
);
const develop = series(compile, serve);

module.exports = {
  build,
  develop,
  clean,
}